1. Field of Invention
The invention relates to compressed storage method and, in particular, to a compressed storage method of the interpolation parameters in digital pictures.
2. Related Art
Interpolation is a way to extract the information of an intermediate point between known points in a picture. We know that a picture consists of pixels. When we magnify, shrink, or rotate a picture, the pixels are reorganized to produce new pixels. Therefore, the interpolation is used to reduce damages to the original picture due to the geometrical transformation. The interpolation method is a common method used when redistributing pixels; the purpose is to determine information of an intermediate point between known points in the picture.
Traditionally, there are many interpolation methods for processing digital pictures. The most common two high-resolution interpolation methods are the bicubic method and the bilinear method. Each pixel in the picture output by the bilinear interpolation algorithm is a result computed from four (2×2) pixels in the original picture. The bicubic interpolation algorithm is an improved method. Each pixel output by this algorithm is a result computed from sixteen (4×4) pixels of the original picture.
Although these two algorithms can achieve good effects, they are very time-consuming. They are local operations and, therefore, involve larger computation loads. The processing speed of interpolation during picture zooming is lower. Moreover, there usually involves more parameters. Thus, they require much larger storage space.